Global environmental concerns on the toxicity of lead-based piezoelectrics impel the great mass fervor on investigations of lead-free alternatives.Barium titanate(BaTiO3,BT)ceramics,the first discovered perovskite fer...Global environmental concerns on the toxicity of lead-based piezoelectrics impel the great mass fervor on investigations of lead-free alternatives.Barium titanate(BaTiO3,BT)ceramics,the first discovered perovskite ferroelectrics,were widely employed to fabricate dielectric capacitors from 1950s.Since a piezoelectric breakthrough was achieved via chemical modification,intensive researches have been performed embracing lead-free BT-based piezoelectrics and their extensional functionalities.In this review,we encompass the stateof-the-art progress on chemical modification tuning phase structure toward advanced electrical properties in BT-based ceramics.Generally,modulated regularity of cations substitution on phase transition is summarized and clarified.Then,we highlight the common methodologies of phase structure(phase boundary,relaxor phase,room-temperature phase transition,etc.)design for optimizing piezoelectricity,electrostrictive strain,electrocaloric,dielectric energy storage or permittivity performances,and cover the noticeable developments and relevant physical mechanisms.Finally,perspectives and challenges on future research issues are featured.This review proposes to exert the significant guidance and service for material design of BT-based and other lead-free perovskite materials with superior functionalities.展开更多
Superhydrophobic cellulose-based products have immense potential in many industries where plastics and other polymers with hydrophobic properties are used.Superhydrophobic cellulose-based plastic is inherently biodegr...Superhydrophobic cellulose-based products have immense potential in many industries where plastics and other polymers with hydrophobic properties are used.Superhydrophobic cellulose-based plastic is inherently biodegradable,renewable and non-toxic.Finding a suitable replace-ment of plastics is highly desired since plastics has become an environmental concern.Despite its inherent hydrophilicity,cellulose has unparalleled advantages as a substrate for the produc-tion of superhydrophobic materials which has been widely used in self-cleaning,self-healing,oil and water separation,electromagnetic interference shielding,etc.This review includes a compre-hensive survey of the progress achieved so far in the production of super-hydrophobic materials based on cellulose and fiber networks.The methodologies and applications of superhydrophobic-modified cellulose and fiber networks are emphasized.Overall,presented herein is targeting on summarizing some of the aspects that are critical to advance this evolving field of science which may provide new ideas for the developing and exploring of superhydrophobic and green-based materials.展开更多
The regional heat flux exchange between heterogeneous landscapes and the nearby surface layer （SL） is a key issue in the study of land-atmosphere interactions over arid areas such as the Heihe River basin in northwe...The regional heat flux exchange between heterogeneous landscapes and the nearby surface layer （SL） is a key issue in the study of land-atmosphere interactions over arid areas such as the Heihe River basin in northwestern China and in high elevation areas such as the Tibetan Plateau. Based on analysis of the land surface heterogeneity and its effects on the overlying air flow, the use of SL observations, atmospheric boundary layer （ABL） observations, and satellite remote sensing （RS） measurements along with three parameterization methodologies （here, termed as the RS, tile, and blending approaches） have been proposed to estimate the surface heat flux densities over heterogeneous landscapes. The tile and blending approaches have also been implemented during HEIhe basin Field Experiment （HEIFE）, the Coordinated Enhanced Observing Period （CEOP） Asia-Australia Monsoon Project on the Tibetan Plateau （CAMP/Tibet）, the Arid Environment Comprehensive Monitoring Plan ＇95 （AECMP＇95）, and the DunHuang Experiment （DHEX）. The results showed that these two proposed parameterization methodologies can be accurately used over heterogeneous land surfaces.展开更多
This paper discussed theory and methodologies of debris-flow risk assessment and established an implementation process according to indicators of debris-flow hazard degree, vulnerability, risk degree, etc. Among these...This paper discussed theory and methodologies of debris-flow risk assessment and established an implementation process according to indicators of debris-flow hazard degree, vulnerability, risk degree, etc. Among these methodologies, historical and potential hazard degree was comprehensively considered into hazard assessment and hazard index was presented to indicate the debris-flow hazard degree. Regarding debris-flow vulnerability assessment, its statistical data and calculating procedure were based on the hazard-degree regionalization instead of administrative divisions, which improved the assessing scientificity and precision. These quantitative methodologies integrated with Geography Information System （GIS） were applied to the risk assessment of debris flows in the upper reach of Yangtze River. Its results were in substantial agreement on investigation data and the actual distribution of debris flows, which showed that these principles and methodologies were reasonable and feasible and can provide basis or reference for debris-flow risk assessment and disaster management.展开更多
Circular RNAs(circRNAs) are covalently closed single-stranded RNA molecules, which are widespread in eukaryotic cells. As regulatory molecules, circRNAs have various functions, such as regulating gene expression, bind...Circular RNAs(circRNAs) are covalently closed single-stranded RNA molecules, which are widespread in eukaryotic cells. As regulatory molecules, circRNAs have various functions, such as regulating gene expression, binding mi RNAs or proteins, and being translated into proteins, which are important for cell proliferation and cell differentiation, individual growth and development, as well as many other biological processes. However, compared with that in animal models, studies of circRNAs in plants lags behind and,particularly, the regulatory mechanisms of biogenesis and molecular functions of plant circRNAs remain elusive. Recent studies have shown that circRNAs are wide spread in plants with tissue-or developmentspecific expression patterns and are responsive to a variety of environmental stresses. In this review, we summarize these advances, focusing on the regulatory mechanisms of biogenesis, molecular and biological functions of circRNAs, and the methods for investigating circRNAs. We also discuss the challenges and the prospects of plant circ RNA studies.展开更多
基金Key Technologies Research and Development Program of Sichuan Province,Grant/Award Number:2018JY0007National Natural Science Foundation of China,Grant/Award Number:51722208。
文摘Global environmental concerns on the toxicity of lead-based piezoelectrics impel the great mass fervor on investigations of lead-free alternatives.Barium titanate(BaTiO3,BT)ceramics,the first discovered perovskite ferroelectrics,were widely employed to fabricate dielectric capacitors from 1950s.Since a piezoelectric breakthrough was achieved via chemical modification,intensive researches have been performed embracing lead-free BT-based piezoelectrics and their extensional functionalities.In this review,we encompass the stateof-the-art progress on chemical modification tuning phase structure toward advanced electrical properties in BT-based ceramics.Generally,modulated regularity of cations substitution on phase transition is summarized and clarified.Then,we highlight the common methodologies of phase structure(phase boundary,relaxor phase,room-temperature phase transition,etc.)design for optimizing piezoelectricity,electrostrictive strain,electrocaloric,dielectric energy storage or permittivity performances,and cover the noticeable developments and relevant physical mechanisms.Finally,perspectives and challenges on future research issues are featured.This review proposes to exert the significant guidance and service for material design of BT-based and other lead-free perovskite materials with superior functionalities.
基金This work is supported by NSERC Canada and funding for the Joint International Research Lab of Lignocellulosic Functional Materials at Nanjing Forestry University.
文摘Superhydrophobic cellulose-based products have immense potential in many industries where plastics and other polymers with hydrophobic properties are used.Superhydrophobic cellulose-based plastic is inherently biodegradable,renewable and non-toxic.Finding a suitable replace-ment of plastics is highly desired since plastics has become an environmental concern.Despite its inherent hydrophilicity,cellulose has unparalleled advantages as a substrate for the produc-tion of superhydrophobic materials which has been widely used in self-cleaning,self-healing,oil and water separation,electromagnetic interference shielding,etc.This review includes a compre-hensive survey of the progress achieved so far in the production of super-hydrophobic materials based on cellulose and fiber networks.The methodologies and applications of superhydrophobic-modified cellulose and fiber networks are emphasized.Overall,presented herein is targeting on summarizing some of the aspects that are critical to advance this evolving field of science which may provide new ideas for the developing and exploring of superhydrophobic and green-based materials.
基金under the auspices of the Innovation Projects of the Chinese Academy of Sciences (KZCX2-YW-Q11-01)the Na-tional Natural Science Foundation of China (40825015 and40810059006)+2 种基金the Chinese National Key Programme for Developing Basic Sciences (2005CB422003)the EU-FP7 project "CEOP-AEGIS" (212921)supported by the EC FP6 GMES EA-GLE project (502057) and the International Institute for Geo-Information Science and Earth Observation (ITC), the Netherlands
文摘The regional heat flux exchange between heterogeneous landscapes and the nearby surface layer （SL） is a key issue in the study of land-atmosphere interactions over arid areas such as the Heihe River basin in northwestern China and in high elevation areas such as the Tibetan Plateau. Based on analysis of the land surface heterogeneity and its effects on the overlying air flow, the use of SL observations, atmospheric boundary layer （ABL） observations, and satellite remote sensing （RS） measurements along with three parameterization methodologies （here, termed as the RS, tile, and blending approaches） have been proposed to estimate the surface heat flux densities over heterogeneous landscapes. The tile and blending approaches have also been implemented during HEIhe basin Field Experiment （HEIFE）, the Coordinated Enhanced Observing Period （CEOP） Asia-Australia Monsoon Project on the Tibetan Plateau （CAMP/Tibet）, the Arid Environment Comprehensive Monitoring Plan ＇95 （AECMP＇95）, and the DunHuang Experiment （DHEX）. The results showed that these two proposed parameterization methodologies can be accurately used over heterogeneous land surfaces.
基金the National Natural Science Foundation of China (40671153)the Scientific Research Fund of Hunan Provincial Education Department (05C175) the Knowledge Innovation Program of Chinese Academy Sciences (KZCX2- YW-302)
文摘This paper discussed theory and methodologies of debris-flow risk assessment and established an implementation process according to indicators of debris-flow hazard degree, vulnerability, risk degree, etc. Among these methodologies, historical and potential hazard degree was comprehensively considered into hazard assessment and hazard index was presented to indicate the debris-flow hazard degree. Regarding debris-flow vulnerability assessment, its statistical data and calculating procedure were based on the hazard-degree regionalization instead of administrative divisions, which improved the assessing scientificity and precision. These quantitative methodologies integrated with Geography Information System （GIS） were applied to the risk assessment of debris flows in the upper reach of Yangtze River. Its results were in substantial agreement on investigation data and the actual distribution of debris flows, which showed that these principles and methodologies were reasonable and feasible and can provide basis or reference for debris-flow risk assessment and disaster management.
基金supported by grants of Key project of intergovernmental International Science and Technology Innovation Cooperation, MOST of China (2022YFE0100500)the National Key Laboratory of Crop Genetic Improvement Self-research Program (ZW18B0102)。
文摘Circular RNAs(circRNAs) are covalently closed single-stranded RNA molecules, which are widespread in eukaryotic cells. As regulatory molecules, circRNAs have various functions, such as regulating gene expression, binding mi RNAs or proteins, and being translated into proteins, which are important for cell proliferation and cell differentiation, individual growth and development, as well as many other biological processes. However, compared with that in animal models, studies of circRNAs in plants lags behind and,particularly, the regulatory mechanisms of biogenesis and molecular functions of plant circRNAs remain elusive. Recent studies have shown that circRNAs are wide spread in plants with tissue-or developmentspecific expression patterns and are responsive to a variety of environmental stresses. In this review, we summarize these advances, focusing on the regulatory mechanisms of biogenesis, molecular and biological functions of circRNAs, and the methods for investigating circRNAs. We also discuss the challenges and the prospects of plant circ RNA studies.
